The cornea is an extremely important part of your eye. A healthy cornea is essential for clear, crisp vision. Unfortunately, your cornea is susceptible to a wide array of diseases and conditions.
What is the Cornea?
Your cornea is the clear, dome-shaped surface of your eye. It is made up of several distinct layers, each with it’s own important job. The cornea is responsible for letting light into the eye, and keeping the inner parts of your eye safe from harm. The cornea plays many roles in keeping your eyes healthy.
Common Corneal Diseases
There are many diseases, conditions and injuries that can affect the health of your cornea, and in turn the rest of your eye. It is important to know about these diseases and how to look out for them. Early diagnosis and treatment of these diseases is important to maintaining vision and overall health.
A pinguecula is a yellowish, slightly raised lesion that forms on the surface tissue of the white part of the eye, close to the edge of the cornea. It is caused by UV light exposure without adequate protection from sunglasses with UV-400 blocker and polarization on the front and back surfaces.
Since the level of UV exposure increases geometrically as one approaches the Equator, pingueculas are far more common in Floridians than those who live in northern U.S. Most people with pingueculas tend to have more dry eye symptoms, a mild foreign body sensation, and occasional irritation.
Without the correct sunglass protection, pingueculas will continue to grow and eventually cover the corneal surface. Now the growths are referred to as pterygium. They form a wedge or wing-shaped growth of benign fibrous tissue with blood vessels overlying and within the growths. With correct sunglass protection, again, consisting of UV-400 blocker and polarization on both lens surfaces, the pterygium almost always will stop growing . However, without the sunglass protection, they continue to grow and can interfere with, especially when they begin to encroach on the pupil. The development and progression of pterygium is very much preventable. Please watch this video for an extensive elaboration on pingueculas and pterygium.
Much like a watch crystal covering the face of a wristwatch, the cornea is a clear dome that covers the eye. It is made up of 5 separate layers; the outermost layer is called the epithelium. Underneath the epithelium, providing precise sensation to the eye, are more nerve fibers per square inch than found in any other part of the human body. When the epithelium is intact, it serves to both cover these nerve fibers and to protect the eye from bacteria and other microbes from entering the eye. However, when the cornea is scratched, it’s this epithelium that becomes damaged, resulting in an increased risk of infection and in exquisite, severe pain as thousands of exposed nerve fibers send pain signals straight up to the brain. Some patients describe the pain of a scratched cornea like someone sticking a knife into their eye, pulling it out, and sticking it back in repeatedly. Aside from the horrendous pain, patients often experience blurred vision, sensitivity to light, and profuse tearing of the eye.
One of the most common causes of corneal abrasions is actually from a fingernail hitting the exposed corneal surface. While this may sound unusual, it’s actually quite common. Contact lens wearers often suffer corneal abrasions from inserting, removing, or over wearing their contact lenses, or from a foreign object becoming trapped between the contact lens and the surface of the eye, causing rubbing and damage. Other causes include babies or toddlers reaching up and accidentally scratching their parent’s or loved one’s eyes with their fingernails, or from individuals rubbing their own eye or attempting to put drops in and inadvertently scratching their corneas.
Seeking early treatment for a scratched cornea is crucial because, with the eye’s protective barrier damaged, any microbe that enters the eye poses a risk for severe, damaging infections. Unlike a typical eye infection, one that results from a scratched cornea causes a complication called a corneal ulcer. Corneal ulcers can scar over, causing permanent, irreversible vision loss, or worse yet, allow bacteria to gain entry into the eye itself and result in complete loss of the eye. Prompt evaluation and treatment of corneal abrasions, before they ever get infected, is the best way to prevent lifelong eye damage.
To treat a corneal abrasion, eye doctors will use a specialized contact-lens-style band-aid that covers the injured area to allow for healing, to relieve pain, and to prevent infection. This contact lens bandage is left on the eye 24/7, and patients are prescribed eye drops consisting of antibiotics and anti-inflammatories to expedite the healing process.
With proper evaluation and treatment, most corneal abrasions heal nicely without infections, scar tissue, or any permanent eye damage.
Cornea ulcers typically occur as a painful, red eye, with mild to severe eye discharge, sensitivity to light, and increased hearing (often profuse). Additionally, there may be blurry vision, especially if the ulcer situated at, or near, the center of the cornea. This condition is caused by a localized infection, similar to an abscess. Corneal ulcers can cause permanent vision loss due to corneal scarring, or tragically, the loss of the eye if the offending microorganism gains entry into the eye. Therefore, establishing the diagnosis of a corneal ulcer and initiating therapy immediately is of paramount importance. Always call the office immediately if you have symptoms of an ulcer. Dr. Alan Mendelsohn or Dr. Nathan Klein will valuate you ASAP. Please never delay. Alan Mendelsohn, M. D., F.A.C.S., is a cornea fellowship trained specialist from Bascom Palmer Eye Institute.
What causes corneal ulcers?
The vast majority of corneal ulcers are caused by one of four types of infections: bacterial, viral, fungal, or parasitic infections. Bacteria corner ulcers are the most prevalent type of ulcer. They are far more common in contact lens wearers, especially those individuals who utilize extended-wear lenses and those who over wear lenses by not replacing them at correct, regularly scheduled intervals. In both scenarios, over time, the contact lens develops microscopic imperfections, enabling bacteria to become adherence of the lens and precipitate a corneal ulcer. All contact lens wearers, if a red, painful eye develops, must see Dr. Mendelsohn or Dr. Klein immediately.
Herpes simplex virus (HSV-1) may cause a cold sore around the mouth, nose, or in the eye. Up to 95% of the U.S. adult population has HSV-1 though some may never experienced a cold sore. Unfortunately, herpetic eye infections tend to be recurrent. Treatment for herpes simplex eye infections/inflammations works very well and is necessary to prevent scar tissue and other associated damage. A different virus, varicella-zoster causes chickenpox, and may subsequently re-activate into shingles. Varicella zoster may lead to ocular inflammations or infections, including corneal ulcers. Treatment is necessary to prevent/minimize scar tissue and other associated damage. The sooner that you come to the office to be examined and treatment initiated, the better the visual prognosis.
Fungal corneal ulcers are relatively rare. Working in the garden, or in an agricultural setting, with the eye getting poked or plant material getting into the eye can lead to a fungal corneal ulcer. Permanent vision loss often results from fungal-induced corneal ulcers. Other risk factors include improper use of contact lenses, being immunocompromised, or prolonged steroid usage.
Parasitic cornea ulcers are extremely rare but particularly devastating in the loss of vision when they develop. Treatment is usually ineffective, therefore, prevention is of great import. The vast majority of these corneal ulcers develop in contact lens wear or falling in properly cleaning lenses. Lenses should not be cleaned with tap water nor saliva.
No matter the type of infection causing a corneal ulcer, with a red, painful eye, please call to see Dr. Alan Mendelsohn or Dr. Nathan Klein ASAP at the earliest sign of problems.
Corneal Foreign Body
At times things can fly into the eye, frequently becoming embedded within the cornea, the clear dome over the eye. Most common corneal foreign bodies include metal, acrylic, wood splinters, pebbles, and glass. These foreign bodies need to be removed expediently by an eye surgeon so as to prevent a corneal ulcer and/or inflammation, as well as vision reducing scar tissue, which can frequently occur. Additionally, with time, the foreign body gets pushed deeper and deeper into the cornea, sometimes penetrating all the way through the entire cornea, becoming dislodged internal within the eye, referred to as an intraocular foreign body (IOFB). Depending on the type and nature of the foreign body, the presence of an IOFB can destroy the eye if not surgically removed in an expedited fashion.
Fuch’s Dystrophy is an eye disease in which the innermost layer of the cornea, called the endothelium, begins to deteriorate. The endothelium is responsible for keeping the cornea clear and pumping out excess fluid. Without it, the cornea begins to swell and become foggy. There is no known prevention for Fuch’s Dystrophy, and may be genetic. This condition can be improved by the use of hypertonic eye drops, which remove excess water from the cornea. Corneal transplant may also be necessary.
The cornea is usually a smooth, dome-shape. People with keratoconus have weaker, unstable corneas. This results in the cornea budging and taking on a cone-like shape. This shape can make vision very blurry. Keratoconus is a progressive disease, and does not have any known prevention. The onset of this disease usually occurs around age 16. Treatments include corneal collagen crosslinking (CXL), Intacs implants, or corneal transplant.
If you are looking for the right corneal specialist for you, be sure to contact Eye Surgeons and Consultants of Hollywood FL today!